my oscar fish trembles

Question
I got a BIG fish 11 inchs long 5 1/2 inches tall 2 1/2 inch wide YES his  A BEAST Well I use to feed it at work everyday and never noticed what its doing now It whole body trembles likes its have a seizure its weird does it for couple seconds then stops then goes on does it again and again and like I said never noticed it at work far as I know it never did it till I got it to my place anyone got any ideas why its doing this plz help

Answer
Hello Barb:  It sounds like he has a bacterial infection and I would try to treat him with a medicated food for bacterial infections.  I would also make sure the water chemistry is within normal ranges and if needed do small water changes to correct the water chemistry.  I do not recommend medicating the tank... just the fish with food... I find this to be a more effective way to deal with internal bacterial infections.  Please keep me posted on his progress.... Jungle makes a great antibacterial food .... dave